Former congresswoman heads just one of several groups spending millions to influence gun control policy

Giffords and Kelly testified in January at a Senate Judiciary Committee hearing on gun violence. After the former congresswoman was severely wounded at a mass shooting in Tucson, Ariz., in 2011, she and her husband formed the group Americans for Responsible Solutions, which is among several groups airing TV ads to advocate legislative solutions to reduce gun violence.

The new ads unveiled Tuesday by the super PAC headed by ex-Rep. Gabrielle Giffords, D-Ariz., and her husband, Mark Kelly, are just the latest in a wave of gun-related advocacy and political spending.

More than a half-dozen groups on both sides of the debate over gun safety have run broadcast ads in major markets or posted TV-ready ads on their YouTube accounts since President Barack Obama called for tougher firearms measures in his State of the Union address in mid-February, according to a Sunlight Foundation analysis. Though overshadowed in recent weeks by budget fights, the gun issue appears to have lost little steam since the December mass shooting at a Newtown, Conn., elementary school.

The groups range from Independence USA PAC , the super PAC launched by New York City Mayor Michael Bloomberg that spent $2.5 million helping Democrat Robin Kelly win a House special-election primary in Illinois, to the National Rifle Association of America Political Victory Fund. Other groups running or posting ads include Mayors Against Illegal Guns, MoveOn.org, the Progressive Change Campaign Committee, and the grass-roots pro-Obama group Organizing for Action, Sunlight reported.

New players continue to pop up. A new political action committee dubbed Americans for the Protection of Children launched last month. The group’s website publishes the NRA’s purported “enemies list” and declares, “I am a proud enemy of the NRA.” Another group launched and run by concerned mothers, originally dubbed One Million Moms for Gun Control, last month renamed itself Moms Demand Action for Gun Sense in America.

The progressive advocacy group Credo Action also has launched several gun-safety-related petition drives and generated more than 9,000 activist calls to senators to urge passage of legislation to ban assault weapons and high-capacity magazine clips. The Credo Super PAC joined with Progressive USA voters on a field campaign to back Robin Kelly in the Illinois primary race.